The present application relates to compounds for use as therapeutically active substances in the treatment of retinal diseases, and in particular in the treatment of retinal diseases leading to photoreceptor loss or degeneration of the outer retina.
The main feature of neurodegenerative diseases is an increasing loss of nerve cells, resulting in various neurological symptoms. The diseases can arise in different periods of life, which proceed diffusely or generalized and produce specific patterns of damage.
Of particular importance are neurodegenerative diseases of the eye. The retinal degeneration is a decay of the retina, which can finally result in the death of the cells of the retina. One of the most important forms of the retina degeneration is the so-called retinitis pigmentosa (RP) or also referred to as retinopathia pigmentosa. The chief function of the retina is transduction of light into nervous impulses by the rods and the cones. Retinitis pigmentosa is a chronic retinal degeneration where the deterioration is accompanied by abnormal deposits of pigment in the rods of the retina. The disease causes a progressive decrease in peripheral vision leading to malfunction of the side vision. Eventually, the person with retinitis pigmentosa can see only straight ahead so that the patient experiences a condition known as “tunnel vision”.
The therapeutic strategies for treating loss of vision caused by retinal cell damage vary, but they are all directed to controlling the illness causing the damage rather than reversing the damage caused by an illness by restoring or regenerating retinal cells.
WO 2016/073931 discloses a method for the treatment of retinitis pigmentosa in a human that comprises administering to the human a therapeutically effective amount of N-acetylcysteine amide (NACA) which reduces cone cell death in the eye.
EP 2 734 202 discloses a pharmaceutical composition containing 4-bromo-N-(imidazolidin-2-ylidene)-1H-benzimidazol-5-amine as active ingredient for modulating the alpha 2 adrenergic receptors. It was shown that said compound reduced and protected the retina from the damage caused by blue light.
US 2015/290215 discloses a composition comprising clozapine, n-desmethyl clozapine, olanzapine or derivatives thereof for treating a retinal disorder, which is caused by oxidative stress.
US 2016/0213671 relates to a pharmaceutical composition for the treatment or prophylaxis of a neurodegenerative disease, which is not based on a protein-folding disorder comprising as the active agent an inhibitor of the valosin-containing protein (VCP inhibitor).
WO 2014/079850 discloses both substituted heterocyclic compounds which were believed to stimulate adult neuronal stem cells and that said compounds may be used for a plurality of different diseases. However, although neuronal stem cells have the ability to differentiate into several cell types, it cannot be predicted whether said new cell types can be stimulated by the same compounds. However, a significant number of compounds which stimulate neuronal stem cells have no or only a weak activity with regard to other cell types such as retinal precursor cells.
U.S. Pat. No. 6,117,675 discloses stem cells isolated from the retina of mammals and retinal cells differentiated from these stem cells and a method for obtaining cells from a retinal pigment epithelial layer of a mammal.
There is currently no way to reverse permanent damage to the retina and restore vision. Drug treatments focus on treating the illness and its symptoms to prevent further damage to the retina. There is a need to reverse damage to the retina and restore vision by endogenously generating new retinal cells or transplanting retinal cells.